The present invention relates generally to lighted glasses and, more particularly, to eyeglasses that are especially well-suited for reading in poorly lit areas.
The use of lights and other illuminating devices with glasses is known. Generally, however, they have not been very well adapted for use with reading glasses. As is known, these types of glasses typically are not worn all the time, and are subject to being frequently taken off and put back on. On the other hand, when reading glasses are worn, they should be comfortable enough to encourage their use so that people are not avoiding their glasses and instead straining their eyes to read.
Incandescent light bulbs commonly have been proposed for use with lighted glasses. Unfortunately, such lighting devices generate a significant amount of heat. Smaller, less powerful incandescent lights still may make the wearer feel quite uncomfortable after even a short while due to the proximity of the light source and the wearer""s face. Further decreasing the size of the incandescent lights, to the point where the wearer is comfortable, may cause light output to be very dim and therefore unusable for illuminating reading material that are held at distances optimal for reading.
For example, if reading distance after using corrective lenses for those in need of vision correction of ordinary size text, e.g. 10 or 12 point font, is optimally ten to eighteen inches from the eyes, a light that is capable of brightly illuminating the pages within that range of distances is necessary for ensuring comfort in reading in dimly lighted areas. However, a lower intensity light bulb, which may be preferable to reduce heat or increase battery life, may result in less than optimal lighting at the optimal reading distance, causing eye-strain and discomfort. In other words, the lower intensity of the light source will result in a decrease in the brightness of the light on the page so that the text to be read is only dimly lit.
The use fiber optic lighting devices instead of incandescent light bulbs is known. In such devices, optical fibers are bundled together to create a light producing device. The nature of fiber optics is such that there is no heat generated at the point where the light is typically transmitted; that is, adjacent the user""s temple. Unfortunately, such devices suffer from a rather major limitation. Namely, a very intense and powerful light source must be available to provide light to the optical fibers. As such, head gear such as worn by surgeons having a fiber optic lighting device must at all times stay tethered to a fiber optic light source, which severely restricts the mobility of the user and thus the ease of use of the headgear. A portable light source that stays connected to the fiber optic light head via electrical cables is less than desirable in terms of the need to be able to conveniently carry the light source, and the inconveniences associated with dangling connecting lines.
An additional problem that exists with fiber optic devices, as well as incandescent lighting devices, is rapid battery consumption. Incandescent light bulbs are known to consume large amounts of power. Similarly, a fiber optic device, since it requires a strong lighting source, also requires a large amount of power. As a result, the user is be forced to change batteries often or stay tethered to a constant power source or light source.
Another disadvantage in prior art lighting devices is the manner in which surfaces are illuminated. Lighting devices used in the medical field generally produce a single fixed narrow beam of light to brightly illuminate the particular stationary body area on which the doctor may be operating. However, such a single narrow beam would not be particularly helpful in reading textual material as the beam would have to be continually shifted across the page being read. On the other hand, lights used with glasses generally tend to be very inefficient in their use of the light they generate as large amounts of light are cast beyond the field of view of the glasses. Adjustable lights are less than desirable as they require a user to make sure the lights are properly positioned each time the glasses are used.
Accordingly, there is a need for lighted glasses that are optimized for use in poorly lit or dim areas. More particularly, reading glasses having lights that are arranged to direct an optimum amount of light to the area where it is required most, i.e. the reading area, is needed. Further, lights that are very compact and lightweight, while still providing the necessary lighting strength and having a sufficiently long life for the power source that power these lights would be desirable.
In accordance with the present invention, lighted glasses, and preferably those adapted for reading which include corrective lenses, e.g. magnifiers, are provided to enable conventional sized text to be clearly read in dimly lit areas when held at a normal range of reading distances at which a user typically reads such material, such as between ten inches and eighteen inches from the lenses. High strength lights and light mounts therefor cooperate to light the reading area with a maximum amount of light provided in the reading distance range. More particularly, highly efficient and high intensity light emitting diodes (LEDs) are mounted in housings configured to fix narrow beams of light to be directed slightly inward toward each other so that the beams overlap in the reading distance range thus providing double the amount of light for reading over that provided by a single one of the lights. To this end, the housings are attached adjacent outer portions of the lenses so that the inwardly directed light beams light up the areas generally in front of the glasses, i.e. in its field of view, and which begins spaced forwardly therefrom, i.e. generally coinciding with the start of the reading distance range. Further, the small size and efficient nature of the preferred solid-state material, i.e. InGaN (indium gallium nitride), for the LEDs, allows very small power supplies to be used such as disc-shaped coin cell batteries for powering the LEDs which, in turn, allows both the light source and power source herein to be self-contained in a highly compact housing therefor. In this regard, the present invention also contemplates the provision of compactly sized lighting modules as described above that can be attached to reading or other glasses either removably or fixed in a more permanent fashion as described hereinafter, or to other items typically worn as headgear such as hats or the like.
The beams of light from the LEDs generate conical-shaped lighted areas such that upon intersection they cooperate to form a conical overlapping lighted area in which the brightness of the light is effectively doubled over that provided by a single LED. The conical overlapping lighted area increases in size as distances increase from the lenses. As is known, light tends to dissipate the further it is from its source. The overlapping conical lighted area is such that the peripheral areas in the field of view of the lenses that do not receive the double light strength of the overlapping light beams are closest to the lenses where light dissipation has its least effect in the reading distance range, whereas the overlapping lighted area increases in size further from the lenses with a corresponding decrease in the single light strength peripheral areas on either side of the cone of overlapping light. Thus, as light dissipates and distances increase from the lenses, the lighting provided will not suffer as the double light strength of the overlapping conical region of light will more than make up for the effects of light dissipation in the reading distance range.
To achieve the optimum amount of light flooding in the reading area, the light housings have surfaces configured to orient the central axis of the conical light beams in a direction that is canted slightly inward with the beams directed toward each other. The preferred canting of the narrow light beams which in the preferred and illustrated form are cones forming angles of twenty degrees is such that the cone axis has a fifteen degree angle with a reference line extending straight forwardly from the lenses. The lenses are preferably magnifiers of a predetermined diopter rating selected by a user so that conventionally sized text such as ten or twelve point font can be clearly read at distances ranging from between approximately ten and eighteen inches forwardly of the user. And it is in this distance range where the overlapping cone of light is formed by the conical light beams canted inward toward each other, as described. In this way, the present lighted reading glasses are provided with lights whose light beams are directed in a carefully coordinated manner with the vision correction provided by the corrective reading lenses so that the amount of light is maximized where it is needed most, i.e. in the field of view of the lenses and within the range of distances at which conventional sized printed text is most commonly read.
In a preferred form, the glasses include temple arms that extend rearwardly from the outer portions of the lenses with the housings attached to the arms toward the forward ends thereof. The temple arms can be opened for use or folded when not in use. With the temple arms opened, the housings are each oriented to project light therefrom forwardly inwardly and toward the light emanating from the housing attached on the other arm. The temple arms toward their forward ends typically will extend substantially straight rearwardly generally normal to the lens frame portions so that the longitudinal axis of the housing is likewise in a normal orientation to the lens frame with the mounting surfaces of the housing configured to be canted inwardly therefrom to direct the light beams as earlier described. Should the configuration of the temple arms and/or housings vary from that described herein, the mounting surfaces can be configured to adapt accordingly such that the light beams are inwardly directed as desired.
The preferred LEDs herein are a small lightweight device that provide a very bright light, while consuming very little power. As such, the batteries enclosed in the housing are small and do not need to be changed as frequently as devices that utilize incandescent lights or fiber optics, which require large batteries. The LEDs provide a relatively narrow beam of light that can be well focused in a particular direction. For example, if two light modules are mounted on a pair of glasses, the LEDs in each module are positioned such that the cones of light produced by the LEDs in the light modules begin intersecting at a point closely adjacent to or coinciding with the start of the range of ideal reading distances. As such, the illuminated reading portion receives the brightest light possible since the intersection of both cones of light are trained on that area. Another advantage of using the high intensity LEDs is that because they consume such a small amount of power, virtually no heat is dissipated. Therefore, a user is able to wear eyeglasses having the light modules mounted thereon, for longer periods of time without suffering from heat and without being bothered by the weight of the devices.
In another form, the light modules are provided with spring clips that are attached to the light module housing. The spring clips are preferably a resilient material such as metal or sturdy plastic. The spring clips enable the light module to be removably attached to any pair of eyeglasses. In still another form of the invention, the light modules are fixedly mounted on clip-on glasses. In particular, the light modules are mounted in the temple area of the clip-on glasses to enable the LEDs in the light modules to project light in the manner described above.